Study Sheet for Chapter 2 Honors Biology
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Transcript of Study Sheet for Chapter 2 Honors Biology
Study Sheet for Chapter 2Honors Biology
EXTENDED RESPONSE TIPS:
• EXAMPLE: • Surface tension caused by the pulling in of H-
bonds of the water molecules. This creates a “film” on the surface of the water.
• This allows small insects to walk on the surface of water.
#1Atom = 1 unit – smallest unit of an element
• Symbol = abbreviation of an element
• Element = 1 kind of substance that cannot be broken down by chemical means – listed on Periodic table
Molecule = 2 or more atoms chemically bonded (can be same or different)
• Formula = abbreviation of a compound
• Compound = 2 or more different elements bonded together chemically
#2
• 59 • Co• 27• Mass number = 59• Atomic number = 27• Number of protons = 27• Number of electrons = 27• Number of neutrons = 32
#3
• Trace elements
• Appear in very small amounts• Milligrams (mg)
#4
• Radioactive isotope
• Breaks down spontaneously• (gives off energy and particles, can be
detected on a PET scan)• Break down to their more stable form• EX: C-14 to C-12
#5
• Why do atoms join to form compounds?
• TO FILL THEIR OUTER ELECTRON SHELL
#6
• IONS and ISOTOPES
• IONS = differ in the number of electrons (charged atoms)
• ISOTOPES = differ in the number of neutrons (different mass numbers)
#7
• Electrons in covalent and ionic bonds
• COVALENT = electrons are shared
• IONIC = electrons are transferred (lost/gained)
#8
• Solute and solvent and solution
Water = solvent – does the dissolving (larger amount)
Sugar = solute –being dissolved
Both = solution
#9
• H-bonding
• When water reaches 4oC and below H-bonds form an open lattice (less dense)
• For surface tension, H-bonds pull the water molecules inward to form a “film”
#10
• IN ORDER (strongest to weakest):
• COVALENTIONICH-bonding
Van der Waals
#11
• Buffers
• Minimize the change in pH by adding extra H+ and OH-
#12
• ACIDS put H+ ions into solution• (H+ donors)
• BASES put OH- ions into solution• (OH- donors)
#13
• Water has high heat of vaporization (slow to heat and also slow to cool)
• So the coastal area temperatures would change less rapidly than inland areas
#14
ACIDS
• Strong 1-3• Weak 4-6
• pH 3 = [H+] 10-3
• pH 4 is 100 X’s the H+ ions than pH 6
BASES
• Strong 11-14• Weak 8-10
• pH 11 = 10-11
#15
• Electrons fill• 2• 8• 8
#16
• ACID PRECIPITATION• pH lower than 5.2
#17• COVALENT BONDS
How can they be written?
• Single bond double bond triple bond
• C-C C=C C=C
• C:C C::C C:::C
• 2 e- 4 e- 6 e-
#18
• H+ ions surround Cl-
• OH- ions surround Na+
#19
• REACTANTS PRODUCTS• Left of arrow right of arrow
#20
+1 +2 share -3 -2 -1 0
e- in outer shells
Ion formed
e- in outer shell
Full outer e-shells
H
8
#20
• Elements that are located in the same column behave more alike chemically
#21
• Polar Covalent = unequal sharing of e-
• Nonpolar Covalent = equal sharing of e-
#22
• Bohr Model
#23
H-H O-H NaCl
#24
• UNIQUE PROPERTIES OF WATER
• 1. H-bonding• 2. Polarity
#25
• CHON
• Trace element in mg
#25
• Fe• Used by RBC to carry oxygen in hemoglobin
• I• used to prevent blindness and have proper
use of thyroid
• F• used to prevent tooth decay•
#26
• Elements have different numbers of protons
• Elements have different numbers of electrons (form different ions and different bonds)
#26
• Same column have same outer shell (valence) electrons
+1 +2 share -3 -2 -1 0
e- in outer shells
Ion formed
e- in outer shell
Full outer e-shells
H
8
#27
• ISOTOPES OF AN ELEMENT• Same number of protons (same atomic
number)• Different number of neutrons (different mass
number)
#28
• Valence electrons (fill inner shell first)• 2• 8• 8
Fill in the chart of e-
Element Number of e-
First shell Second Third
Shell Shell
carbon 6 2 4
lithium 3 2 1
Sodium 11 2 8 1
Oxygen 8 2 6
#29
• If atomic number 8• Can form two more bonds
#30
• BOTH INTERMOLECULAR
• Van der Waals = are momentary very weak forces of attraction between nonpolar molecules resulting from uneven electron distributions(EX: gecko hairs on feet and glass)
• H-bonding = forces between H and F, O, or N
#31
• Cations = (+) ions
• Anions = (-) ions
#32
You need to break the H-bonds to vaporize (form a gas)- takes extra time
You need to form H-bonds to form ice – takes extra time
#33• pH [H+] [OH-] [H+] X [OH-]
• 0 1 X 10-0 1 X 10-14 1 X 10-14
• 1 1 X 10-1 1 X 10-13 1 X 10-14
• 2 1 X 10-2 1 X 10-12 1 X 10-14
• 3 1 X 10-3 1 X 10-11 1 X 10-14
• 4 1 X 10-4 1 X 10-10 1 X 10-14
• 5 1 X 10-5 1 X 10-9 1 X 10-14
• 6 1 X 10-6 1 X 10-8 1 X 10-14 acid
• 7 1 X 10-7 1 X 10-7 1 X 10-14 neutral
• 8 1 X 10-8 1 X 10-6 1 X 10-14 base
• 9 1 X 10-9 1 X 10-5 1 X 10-14
• 10 1 X 10-10 1 X 10-4 1 X 10-14
• 11 1 X 10-11 1 X 10-3 1 X 10-14
• 12 1 X 10-12 1 X 10-2 1 X 10-14
• 13 1 X 10-13 1 X 10-1 1 X 10-14
• 14 1 X 10-14 1 X 10-0 1 X 10-14
Determine the pH• [H+] [OH-] = 10-14
•If [H+] = 10-4 = pH 4•[OH-] = 10-10
#34
• Mg-2 Cl-
• K+ I-
• Ca+2 P-3
#35
• REVIEW YOUR ELEMENTS AND SYMBOLS:
• Ca = calcium• C = carbon• Co = cobalt
#36 EXAMPLE
• Why water makes a nice drop on wax paper:• Surface tension on the water.• Strong cohesion of the water molecules• Weak adhesion to the wax paper.
• Review blue sheet, water properties quiz and lab.